The victims are ONGC's Residential Chief Plant Supervisor C.N. Rao, aged 50, and Central Industrial Security Force (CISF) jawans of the Fire Wing (ONGC Unit), who were killed in the line of duty, are E. Nayaka, M.K. Paswan and S.P. Kushwaha.
Police said that according to information received by them, around 6.45 a.m., the CISF fire brigade was alerted of a gas leak near the LPG plant on the complex and a team of ONGC and CISF personnel rushed to the spot.
They managed to detect and close a leaking valve and were waiting to observe if there were more leaks, but suddenly there was a huge blast followed by a massive fire, killing the three CISF firemen and the plant supervisor.
Even as reinforcements were summoned, the others continued to fight the blaze in which three were hurt and hospitalised.
According to preliminary reports, the suspected cause of the fire could be a leakage and a blast in one of the pipelines in the sprawling high-security complex which is out of bounds for all.
Local eyewitnesses said they heard a huge explosion and within seconds, saw the inferno with clouds of dark smoke billowing out of the conflagration on the ONGC complex, which was visible for several kms around.
"There is no impact on oil processing. Gas has been diverted to Hazira plant (in Gujarat). The situation is being assessed," an ONGC spokesperson told earlier on Tuesday.
The blaze was brought under control after nearly three hours and then cooling operations taken up. Preliminary reports indicate massive damage to the gas and oil pipelines which could disrupt supplies to consumers for some time.
In an immediate fall-out of the fire, gas supplies of both PNG and CNG were severely hit in Mumbai, according to Mahanagar Gas Ltd. (MGL).
The Mahanagar Gas Ltd, which supplies domestic, industrial and vehicular gas, said that gas supply to its City Gate Station, Wadala, has been badly affected.
"We are ensuring that supply to domestic PNG consumers is maintained on priority without interruption. However, many CNG stations in Mumbai may not operate due to low pressure in the pipeline," the spokesperson said.
By evening, the MGL said supply to the Wadala station was partially restored and supply to CNG stations, industrial and commercial customers were being progressively restored.
The MGL network is spread across entire Mumbai, parts of Thane, Palghar and Raigad, serving lakhs of domestic, industrial and other consumers.
The CISF lauded the services of its three jawans who lost their lives in the mishap this morning.
"The CISF salutes the supreme sacrifice of CISF Fire Wing bravehearts who sacrificed their lives in the line of duty during the fire-fighting operations at ONGC Uran, Navi Mumbai," the CISF said in a tribute.
It added that the CISF will be forever indebted for their bravery and commitment and their alertness averted a potentially major tragedy on Tuesday.
Besides the ONGC's own fire service and crisis management teams, 22 fire-fighting teams from Uran, JNPT, Navi Mumbai, Reliance and surrounding areas helped battle the blaze.
( With inputs from IANS )